Diesel CO2 vs CalcFast
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Diesel CO2
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This is a can calculate the fuel consumption (diesel) and carbon dioxide emissions from utility.
CalcFast
A fast and elegant calculator for Apple devices that displays your calculation history. It offers a Today Extension for quick access and supports Apple Watch, external keyboards, and VoiceOver.
- Calculation history display
- Today Extension for quick calculations
- Apple Watch app
- Dark/light mode selection
- External keyboard support
- VoiceOver support
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Fast and simple calculator for iPad, iPhone and Apple Watch that shows the calculation history, includes a Today Extension that allows for fast calculation by swiping down and 3D Touch for quick interactions. Numbers are formatted for your country, i.e. period in the US and comma in Europe. Ever lost your train of thought half way through a calculation and thought how handy it would be to review your calculations. The aim of this Calculator is to be fast, elegant and simple. Features: - The calculator can open side by side or over other apps in iPadOS. - Select dark or light mode. - External keyboard support. - Smart Apple Watch Calculator included. - Light weight Today Extension included. - Calculations shown when input and on tape. - Key click confirms pressing of buttons, which may be turned off. - Previous calculation is repeated when the equal sign is pressed. - Numbers are shown in local format, depending on your Region Formats, i.e. comma used in Europe. The number of decimal digits may be set in the Settings. - VoiceOver is supported. - Calculations Tape may be deleted by Tapping on it.
Screenshots
Verdict
The clearest difference is update cadence: CalcFast at every 2 months against Diesel CO2's every 10 months. Diesel CO2's advantage is iOS requirement (15.6 vs 27.1). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Diesel CO2 ships an update every 10 months, CalcFast every 2 months. The most recent releases landed on October 15, 2026 and October 24, 2026 respectively.
| Parameter | Diesel CO2 | CalcFast |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.2 (21 ratings) — better |
| Positive reviews | — | 78.3% of reviews |
| Number of ratings | — | 21 — better |
| Update frequency | Every 10 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 27.1 |
| Further details — not scored | ||
| Size | 2 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | Addison Mai | Hannes Sverrisson |
In-app purchases
Diesel CO2
No in-app purchases
CalcFast
No in-app purchases
Questions
Is Diesel CO2 free?
Is CalcFast free?
Do Diesel CO2 or CalcFast have ads?
Which is updated more often, Diesel CO2 or CalcFast?
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